Explain big O notation

habr.com "We can use Big O notation to compare and search different solutions to find which solution is best. The best solution is one that consumes less amount of time and space. Generally, time and space are two parameters that determine the efficiency of the algorithm.

Big O Notation tells accurately how long an algorithm takes to run. It is a basic analysis of algorithm efficiency. It describes the execution time required. It depends on the size of input data that essentially passes in. Big O notation gives us algorithm complexity in terms of input size. For the large size of input data, the execution time will be slow as compared to the small size of input data. Big O notation is used to analyze space and time."